An Introduction
Let’s see some newer JS features!
Everything covered here is part of ES2015 (what is that??)
Some of these features aren’t supported in IE
Before we start…..A brief history
Browser wars of the 90s
JS Chaos, standardization necessary
Enter ECMA!
What is ECMAScript?
The “standard” for the JS language!
Started during the browser wars between Microsoft and Netscape
Browsers/Node implement the language based on this standard
What is ECMA?
standards organization for information and communication systems.
Who makes the decisions?
Introducing TC39
Technical Committee 39 maintains and updates the ECMAScript standard/
They are “in charge” of adding new features
They evaluate proposals for complementary or additional technologies.
Evolving JS - The old way
New features were batched together into large releases
These releases were named with version numbers (ES3, ES5, etc.)
Versions released infrequently, often with years between
Evolving JS - The new way!
Updates to the standard are published yearly
Any new features ready each year are added together
Versions named by year (ES2016, ES2017, etc.)
Introduced a new, formalized proposal process
Stages of TC39
Stage 0: Strawman
It all starts with an idea!
Non-formal proposals live here
Any discussion, idea, change, or addition which has not yet been submitted as a formal proposal is considered to be a “strawman” proposal at this stage. Only members of TC39 can create these proposals, and there’s over a dozen active strawman proposals today.
Stage 1: Proposal
It’s an “official” proposal
Polyfills / plugins will be introduced usually at this time
Very unlikely that implementers are working on proposals
Stage 2: Draft
Still a bit too early for us to cover!
Sometimes implementers will experiment adding this to browsers/environments
Stage 3: Candidate
Proposals in this stage are candidate recommendations.
Unlikely to change beyond fixes to issues identified in the wild.
Proposals move to this level with at least one browser implementation or when supported by a build-time transpiler like Babel.
Stage 4: Finished
Proposals get to this stage when there are at least two independent implementations that pass acceptance tests.
Everything in this unit is Stage 4
And has been implemented by almost all modern browsers
Let’s get started!